In recent years, the use of light-emitting diodes (LEDs) for various common lighting purposes has increased, and this trend has accelerated as advances have been made in LEDs. Indeed, lighting applications which have been served by fixtures using high-intensity discharge (HID) lamps, halogen lamps, compact florescent light (CFL) and other light sources are now increasingly beginning to be served by LED modules. Such lighting applications include, among a good many others, interior lighting, such as for warehouse spaces.
Illumination of warehouse spaces have specific requirements which dictate the amount of light in certain areas. In particular, warehouse aisles have to be well illuminated with some illumination being directed along tall storage racks for efficient retrieval of stored items and, most importantly, for safe operation of the personnel.
Some efforts have been made to develop LED lenses for directing LED light into a desired light distribution. Some of such lenses are difficult and expensive to manufacture, which increases overall cost for LED lighting using such lenses. Yet such lenses fall short in providing light distribution required for proper illumination of elongate warehouse passageways with tall bordering shelving structures.
It would be highly beneficial to provide a lighting apparatus which produces a desired light distribution for illumination of areas like warehouse aisles and along storage racks accommodating appropriate visibility for stored bulky items with large labels and for small items with small labels. It is further desirable that such lighting apparatus has high efficiency with useful output of maximum emitted light and provides improved uniformity of the light distribution.